Posorja fauna, Guayas (Oligocene to of Ecuador)

Where: Guayas, Ecuador (2.7° S, 80.3° W: paleocoordinates 4.7° S, 74.5° W)

• outcrop-level geographic resolution

When: Posojra Formation, Early/Lower Oligocene to Early/Lower Oligocene (33.9 - 23.0 Ma)

• SOURCE: composite assemblage from small exposures exposed along Guayas River. AGE: Some workers have placed this unit into the Miocene, but the fauna shows no affinities with the Miocene faunas of Zorritos and Amen. More affinity exists with the basal Heath Shale or Calet Mero and possibly equivalent to the Punta Barvo or Heath shales.

• formation-level stratigraphic resolution

Environment/lithology: marine; lithified sandstone

• ENVIRONMENT: no environmental data reported.
• GENERAL LITHOLOGY:sandstone; lithified based on figures.

Size class: macrofossils

Collection methods: quarrying, ,

• COLLECTOR: unknown collectors, presumably this is a composite of some collecting effort. REPOSITORIES: unknown repsotories

Primary reference: G. Shepard. 1937. The geology of south-western Ecuador. Published by AAPG; lists some otherwise unpublished faunal lists, identified by Woodring and Vaughan; nomenclature is antiquated. [A. Miller/A. Hendy]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 61201: authorized by Austin Hendy, entered by Austin Hendy on 30.05.2006

Creative Commons license: CC BY (attribution)

Taxonomic list

• IDENTIFIER: A.A. Olsson. COVERAGE: probably not exhaustive, but nevertheless lengthy for gastropoda and bivalvia. No other groups mentioned. NOMENCLATURE: antiquated, but largely identified to species resolution.
Gastropoda
 Epitonioidea - Epitoniidae
Epitonium sp. Bolten 1798 wentletrap
 Neotaenioglossa - Calyptraeidae
Crepidula sp. Lamarck 1799 slipper shell
 Cerithioidea - Cerithiidae
Cerithium sp. Bruguière 1789 cerith snail
 Cerithioidea - Turritellidae
Turritella meroensis Olsson 1931 turret shell
 Architaenioglossa - Ampullinidae
Ampullinopsis spenceri Cooke 1919 snail
 Neogastropoda - Olivellidae
"Olivancillaria (Agaronia) cotopaxi" = Agaronia, Olivancillaria (Agaronia) antisana
"Olivancillaria (Agaronia) cotopaxi" = Agaronia snail
 Neogastropoda - Olividae
Olivella (Lamprodoma) sp. Swainson 1840 olive snail
 Neogastropoda - Buccinidae
Siphonalia sp. Adams 1863 true whelk
Phos sp. Monfort 1810 true whelk
 Neogastropoda - Terebridae
Terebra sp. Bruguière 1789 auger snail
 Neogastropoda - Pseudolividae
"Pseudoliva parinasensis" = Pseudoliva (Buccinorbis) parinasensis
"Pseudoliva parinasensis" = Pseudoliva (Buccinorbis) parinasensis Woods 1922 snail
Subspecies: P. parinasensis mancorensis
 Neogastropoda - Thaisidae
"Acanthina (Chorus) sula" = Chorus sula
"Acanthina (Chorus) sula" = Chorus sula Olsson 1931 snail
 Sorbeoconcha - Naticidae
Bivalvia
 Arcida - Arcidae
 Cardiida - Veneridae
Pitaria (Lamelliconcha) wolfi Olsson 1931 venus clam
"Clementia peruviana" = Clementia (Egesta) peruviana Olsson 1928 venus clam
"Chione posorjensis" = Chione (Chionopsis) posorjensis Olsson 1931 venus clam
 Cardiida - Tellinidae
"Tellina (Angulus) sp." = Angulus, Macoma meroensis
"Tellina (Angulus) sp." = Angulus Megerle 1811 tellin clam
Macoma meroensis Olsson 1931 tellin clam